Oil send unit - Physical location on a 1999 Mercury 454

[kgarguilo]

Hello all, I have scoured this site and others and found no info on the actual physical location of the oil send unit for my Mercury 7.4L MPI MIE V-8 gasoline naturally aspirated engine - 330hp SN- 0L303931 & 34 with Velvet Drive Transmissions, Model 20-01-005 direct drive - 2.455:1 ratio.

I will go again tomorrow and search for the units as I am adding an additional oil send unit for my Fox Marine Mefi 3 engine gateways. In looking through the service manual Mercury 90-861326-01. I do not see a pictural view that shows the location either. I will try going page by page tonight but thought maybe someone on here may know exactly where it is at.

Once done I will write it up as a project to share. I already have the Engines connected and templates programed on my Garmin 8612 vsx. Looking forward to wrapping this project up. Thanks in advance.

[bud37]

Have a look, back of block top, near the distributor. May have to move some harness to see.

You are asking about the sender and not the low pressure switch ?

[kgarguilo]

QR_BBPOST Have a look, back of block top, near the distributor. May have to move some harness to see.

You are asking about the sender and not the low pressure switch ?

KG Thanks Bud, I will look in the morning and let you know. Yes, the pressure sender to the guage. Fox Marine supplies a TEE so there oil pressure switch can be added to read on the mefi 3 gateway.

[kgarguilo]

I looked this morning and see a switch in the location behind and port side of the distributer as you suggested and disconnected the light blue wire that goes to it, started the engine and the oil pressure gauge still works, is something else feeding that gauge?
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Oil pressure switch.jpg

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[bud37]

I think you found the switch......look for something that looks something like this.....I am not sure then where exactly that sender is , sorry

[kgarguilo]

I think you found the switch......look for something that looks something like this.....I am not sure then where exactly that sender is , sorry

For future reference, here is where the oil pressure switch is located. A shout out to Alan at Fox Marine and some videos and pics online that helped to find it. The guidance I received from Alan was, it should be on the port side of the engine and almost at the back and then I found this picture. Note, it was hard to see as when they sprayed the engine black at the factory I guess, they also sprayed the oil pressure switch making it hard to see as it was covered by wire harnesses.

image003.png

FYI I am doing a video on the install and will supply a link once it is completed.